Federico Cargnelutti has posted the third part of his series looking at his alternative to the normal Zend_Controller in Zend Framework applications - Zf_Controller. This article focuses on its interface with the model.
The domain layer is separated from the other layers and has no dependencies on Zf_Controller. Adding the domain directory to your include path allows you to load and access Model classes from anywhere within your project.
His code examples show an IndexController extending the Zf_Controller and how a Model can be called from inside it through a getInstance (as long as the model directory is in your path). You can take a look at part one and part two for more information on this alternative component.